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The Suicide Detective

Matthew K. Nock, director of the Laboratory for Clinical and Developmental Research at Harvard University, is one of the most original and influential suicide researchers in the world.Credit
David Wright/Redux, for The New York Times

For reasons that have eluded people forever, many of us seem bent on our own destruction. Recently more human beings have been dying by suicide annually than by murder and warfare combined. Despite the progress made by science, medicine and mental-health care in the 20th century — the sequencing of our genome, the advent of antidepressants, the reconsidering of asylums and lobotomies — nothing has been able to drive down the suicide rate in the general population. In the United States, it has held relatively steady since 1942. Worldwide, roughly one million people kill themselves every year. Last year, more active-duty U.S. soldiers killed themselves than died in combat; their suicide rate has been rising since 2004. Last month, the Centers for Disease Control and Prevention announced that the suicide rate among middle-aged Americans has climbed nearly 30 percent since 1999. In response to that widely reported increase, Thomas Frieden, the director of the C.D.C., appeared on PBS NewsHour and advised viewers to cultivate a social life, get treatment for mental-health problems, exercise and consume alcohol in moderation. In essence, he was saying, keep out of those demographic groups with high suicide rates, which include people with a mental illness like a mood disorder, social isolates and substance abusers, as well as elderly white males, young American Indians, residents of the Southwest, adults who suffered abuse as children and people who have guns handy.

But most individuals in every one of those groups never have suicidal thoughts — even fewer act on them — and no data exist to explain the difference between those who will and those who won’t. We also have no way of guessing when — in the next hour? in the next decade? — known risk factors might lead to an attempt. Our understanding of how suicidal thinking progresses, or how to spot and halt it, is little better now than it was two and a half centuries ago, when we first began to consider suicide a medical rather than philosophical problem and physicians prescribed, to ward it off, buckets of cold water thrown at the head.

“We’ve never gone out and observed, as an ecologist would or a biologist would go out and observe the thing you’re interested in for hours and hours and hours and then understand its basic properties and then work from that,” Matthew K. Nock, the director of Harvard University’s Laboratory for Clinical and Developmental Research, told me. “We’ve never done it.”

It was a bright December morning, and we were in his office on the 12th floor of the building that houses the school’s psychology department, a white concrete slab jutting above its neighbors like a watchtower. Below, Cambridge looked like a toy city — gabled roofs and steeples, a ribbon of road, windshields winking in the sun. Nock had just held a meeting with four members of his research team — he in his swivel chair, they on his sofa — about several of the studies they were running. His blue eyes matched his diamond-plaid sweater, and he was neatly shorn and upbeat. He seemed more like a youth soccer coach, which he is on Saturday mornings for his son’s first-grade team, than an expert in self-destruction.

At the meeting, I listened to Nock and his researchers discuss a study they were collaborating on with the Army. They were calling soldiers who had recently attempted suicide and asking them to explain what they had done and why. Nock hoped that sifting through the interview transcripts for repeated phrasings or themes might suggest predictive patterns that he could design tests to catch. A clinical psychologist, he had trained each of his researchers how to ask specific questions over the telephone. Adam Jaroszewski, an earnest 29-year-old in tortoiseshell glasses, told me that he had been nervous about calling subjects in the hospital, where they were still recovering, and probing them about why they tried to end their lives: Why that moment? Why that method? Could anything have happened to make them change their minds? Though the soldiers had volunteered to talk, Jaroszewski worried about the inflections of his voice: how could he put them at ease and sound caring and grateful for their participation without ceding his neutral scientific tone? Nock, he said, told him that what helped him find a balance between empathy and objectivity was picturing Columbo, the frumpy, polite, persistently quizzical TV detective played by Peter Falk. “Just try to be really, really curious,” Nock said.

That curiosity has made Nock, 39, one of the most original and influential suicide researchers in the world. In 2011, he received a MacArthur genius award for inventing new ways to investigate the hidden workings of a behavior that seems as impossible to untangle, empirically, as love or dreams.

Trying to study what people are thinking before they try to kill themselves is like trying to examine a shadow with a flashlight: the minute you spotlight it, it disappears. Researchers can’t ethically induce suicidal thinking in the lab and watch it develop. Uniquely human, it can’t be observed in other species. And it is impossible to interview anyone who has died by suicide. To understand it, psychologists have most often employed two frustratingly imprecise methods: they have investigated the lives of people who have killed themselves, and any notes that may have been left behind, looking for clues to what their thinking might have been, or they have asked people who have attempted suicide to describe their thought processes — though their mental states may differ from those of people whose attempts were lethal and their recollections may be incomplete or inaccurate. Such investigative methods can generate useful statistics and hypotheses about how a suicidal impulse might start and how it travels from thought to action, but that’s not the same as objective evidence about how it unfolds in real time.

The inscrutability of suicide has not kept most psychologists who study it from theorizing about why people kill themselves. Nock, however, tends to approach theories from a different angle. “I think it’s easy to generate explanations,” he said recently. “It’s much harder to test out these different explanations and see whether the data support them or not.” At first, the stress of combat seemed to be the obvious reason for the jump in military suicides — until researchers realized that the rate has also risen among soldiers who were never deployed. Public-health experts have speculated that the uptick in suicides among the middle-aged is linked to modern tensions like the troubled economy, the stress of caring for elderly parents and insolvent children, and unprecedented access to prescription drugs. Nock, conversely, tends to point to a graph showing how the suicide rate for 45-to-64-year-olds has dipped and risen over a longer period of time — the rate today is similar to what it was 20 years ago. The graph tells a more complicated story. “My thought is that we’ve had theories of suicide for a long time and no data,” he said. “So we want to work from the other end.”

Indeed, Nock has started from scratch by searching for a way to precisely measure suicide risk. Three years ago, he and his team published a paper suggesting that they had found, for the first time, an objective test that could predict a psychiatric patient’s likelihood of a suicide attempt better than the patient or his clinician could. Nock is now running it and other tests on hundreds of people — those who have tried to kill themselves, those who have had suicidal thoughts and those who have not — to see how the initial scores differ from one group to another and whether those scores will end up having forecasted, beyond what current methods can, who will try to kill themselves in the future.

Each data point Nock collects moves him one step closer to his ultimate goal: to be able to give people a series of tests that could tell them — and their psychiatrists or primary care physicians or school nurses — how high their risk of suicide is at any given moment, much the way cardiologists can use blood-pressure and cholesterol readings combined with weight and height to calculate a person’s risk of heart disease.

Each data point is also a person whose impossibly complex conscious and unconscious thoughts — about who they are, what they want, what’s possible and tolerable — highlight both why such tests are needed and why it is so surprising that they might actually work.

When Melissa was growing up in Southern California, her playmates included six imaginary princesses. One of them was always getting captured, and Melissa, a princess herself, would save her, she told me. We were in a teashop on a February afternoon in Harvard Square, where the clattering dishes, the hiss of steaming milk and the wash of voices cocooned our conversation the way she preferred. Melissa, who asked to be identified only by her middle name, wore a thin, white-checkered coat. She was 18, petite and pale, with faint freckles and auburn hair collected in a silver clip. Last November, she tried to kill herself in her college dorm room with an overdose of pills. Now, three months later, she had completed a residential treatment program at McLean Hospital in Belmont, Mass., and was living in a transitional house in Cambridge for psychiatric patients. She was taking classes at a local extension school; to return to her former college, a liberal-arts academy in another state, she would need to reapply. I first met Melissa in Nock’s lab and was impressed by her cinematic memory. But even for her, trying to recreate the progress of her suicidal thoughts was like trying to trace a breaking wave back out to the ocean. Her parents, her doctors and even Melissa herself had not known the wave was coming until it hit. Now all of them were hoping to turn back future danger without knowing exactly what to look for.

In seventh grade, Melissa said, she sometimes wrote “goodbye notes” in her head in the shower. That year, she started feeling excluded by her friends, and because she was later than other girls to hit her growth spurt, she said, she looked like an outsider too. The notions she had about ending her life were mostly fantasy. “It was never something that I talked about, but it was always kind of there,” she said. She hadn’t considered herself “brave enough” to really do it, though she now thought “brave” was a weird word to use.

Melissa talked about her high-school years with animation, doing goofy voices to narrate the naïve thoughts of her younger self. She recalled mean messages her classmates had posted about her on a popular online forum, even as she sympathized with what she saw as their desire to fit in. Early on, she started drinking regularly and smoking pot. She starved herself. She fought with her parents. Her grades dropped. The summer after her sophomore year, Melissa told her parents that she felt suicidal and needed to go to a hospital; doctors there held her for five days and prescribed medication that her father, a neurobiologist, and her mother, a biochemist, refused because they felt it was far too strong for her, her mother told me. Eventually afraid to leave her alone for even a few minutes, they enrolled her in an inpatient program for substance abuse and mental illness. Melissa felt the counselors there punished her for her behavior instead of helping her learn how to change it, and they held her beyond the month she expected. “They said I was resisting treatment,” she said. “Really the only thing that it taught me was that I have to get myself out of here. To leave, I had to explain why I was manipulative, passive-aggressive, how I relate to boys by expressing my sexuality.” These assumptions offended her, and she didn’t believe they were true. Ultimately, however, she told her doctors what she thought they wanted to hear, and they let her go.

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Lettering by Oliver Jeffers. Tom Schierlitz for The New York Times

Melissa saw a psychiatrist, who prescribed medication for depression and anxiety, and she went through several outpatient programs with better results. She transferred to a new school for her junior year, which eased her social stress; she was a competitive athlete, acted in plays and raised money for impoverished children in India that she delivered in person. She was accepted by her first-choice college. The summer before she left home, at a ceremony at a treatment center, she told me, the mother of another girl said to her, “I don’t understand why you would be here in the first place, because it seems like you have everything figured out.” Outwardly she accepted the remark as a compliment, though it startled her to realize that she seemed to have everyone fooled. “At that exact point in time,” she said, “I was thinking about anything except being alive.”

Her parents, worried, stipulated that they would pay her college tuition only if she attended weekly therapy sessions at the school’s health-services center, which would report missed attendance to them. But Melissa wanted to start over. She skipped sessions and stopped taking her medication — despite the potentially dangerous side effects of quitting abruptly — saving the pills in a baggie instead. Her mother told me she flew out to check on her, but Melissa didn’t want to see her. She was 18 by then and in charge of her own health care. At the teashop, Melissa described how she decorated her new dorm room, putting up a Harry Potter poster she brought from home and making the bed with blue sheets her mother bought for her when she was 13 and scared to go to sleep. She found friends, began drinking and doing drugs again and fell behind in her classes. About a month into the semester, she said, a painful episode between her and a boy she was seeing became campus gossip, making her feel heartbroken and exposed. She couldn’t say exactly how or when she formed a plan to use the pills she had saved as “an emergency-exit measure.”

She tugged at a pink hair tie on her wrist. “I’m having a hard time explaining this,” she told me. “It wasn’t one specific moment. It was just everything.”

I asked her if the therapists she saw ever questioned whether she had suicidal thoughts. “They always asked,” she said. “And the answer I always gave was yes, I had thoughts, and that it was nothing I would act on. It was sort of a robot answer, and it wasn’t really true, but I wasn’t in a position that I could say, ‘No, I love my life,’ and I wasn’t in a position where I could say, ‘Yes, I spend my subway rides planning out my goodbye note.’ ”

On the evening after Halloween, Melissa was hung over and wearing most of her angel costume from the night before, when she and her roommate, dressed as a devil, went to a campus party. A week earlier, she revived the relationship with the boy who hurt her. Now she received a text from him telling her to stop being so needy. She recalled feeling as if everyone would be better off if she disappeared; she wasn’t making the world a better place and didn’t deserve to be in it. Sitting on her bed, she wrote a goodbye letter in her favorite notebook while her roommate and a few of their friends listened to music and did homework. When Melissa’s friends asked if she wanted to go to the dining hall for ice cream, she declined. After they left, she swallowed the pills. She woke from a coma in intensive care, intubated. Paramedics had scissored off her clothes, revealing “Do not resuscitate” scrawled on her forearms in red Sharpie. She didn’t remember writing it.

Melissa found it hard to say why she tried to kill herself when she did — how that night differed from others when she had felt wounded or sad. “Everything just kind of hit me all at once,” she said. “I was behind in my classes. I felt like my friends were embarrassed by me. And, I don’t know, I just felt like I had screwed up my life so badly that this was the only way out.”

Nock didn’t plan to devote his career to researching self-harm. The son of an auto mechanic, he grew up pumping gas and learning to fix cars at the service station his parents own in Basking Ridge, N.J., while also taking other jobs: tuxedo-rental clerk, ice-rink guard, windshield repairer. He was the first member of his family to graduate from college and expected to use his degree in psychology to become a clinician and work with patients. But the more time he spent with people who hurt themselves, the more he worried about treating their behavior. His first internship, while an undergrad at Boston University, was in a psychiatric unit for violent patients prone to severe self-injury: one man pulled out his eyeball, another arrived with deep gashes in his arms. Nock, who rarely mentioned his own feelings even when I asked him personal questions, said he grew close to the youngest patient on the unit, a man about his age. “When he was in treatment, moodwise he was pretty stable, pretty happy guy, pretty upbeat guy,” Nock said. “We’d talk a lot about hip-hop and soccer.” When he was released, around the time Nock’s internship was ending, he killed himself. He was the first person Nock knew who died by suicide, and Nock had not foreseen it. He went on to get a doctorate in psychology from Yale, and instead of joining a clinical practice, he turned to academia and research.

Nothing in medical literature suggests a reliable method for accurately identifying suicidal patients. The earliest known reference to suicide is a poem, written on papyrus in Egypt 4,000 years ago. From then until the 1700s, artists, philosophers and religious figures, rather than doctors or scientists, were the only ones to wrestle with the subject, according to George Howe Colt’s comprehensive history, “The Enigma of Suicide.” It was a sociologist, Émile Durkheim, who offered the first unified theory of suicide, “Le Suicide,” which has underpinned suicide science ever since it was published in 1897. Durkheim argued that suicidal feelings occur in response to a person’s relationship with society: not being part of a community and sudden disruptions in the fabric of daily life are potential triggers. Freud put suicide in the same category as masochism, which he attributed to an aggressively critical superego turning on the self. Recent psychological theories posit that suicide is driven by intense mental pain: hopelessness, a yearning for escape, a sense of not belonging, feelings of burdensomeness.

But suicidal behavior also appears to run in families, suggesting it has biological roots. “We think that there are many genes — there might be hundreds, there might be thousands, each of which might contribute a tiny amount individually” to heightened risk, says Jordan Smoller, a psychiatric geneticist at Massachusetts General Hospital who has collaborated with Nock. Gustavo Turecki, the director of the McGill Group for Suicide Studies, has also shown that one major risk factor linked to suicide, having suffered abuse in childhood, can cause changes in the receptors of brain cells that regulate the stress hormone cortisol, leaving the brain in a chemical state of increased alertness that causes a person to overreact to stress. “Our emotions are all somewhere coded in our brains,” Turecki told me, and identifying what mechanisms drive suicide could one day enable scientists to tailor drug therapies to reduce risk. Right now, though, Nock’s tests appear to offer our best hope for a diagnostic tool that could work on anyone, no matter what complex social and biological factors are prompting suicidal thoughts. They also offer a way of seeing how such thinking operates, which could help us understand why it happens.

In 2003, during his first year teaching at Harvard, Nock approached his colleague Mahzarin Banaji with a proposal. Banaji had helped develop the Implicit Association Test, which was introduced to social psychology five years earlier and has become famous for its ability to measure biases that subjects either don’t care to acknowledge or don’t realize they have on topics like race, sexuality, gender and age. Nock wondered if the I.A.T. could be configured to measure people’s bias for and against being alive and being dead, and Banaji thought it was worth a try. They experimented with several versions in Nock’s lab and at the psychiatric-emergency department at Mass General. Then they put their best one on a laptop and offered it to Mass General patients, many of whom had recently threatened or attempted suicide; 157 agreed to take it. Hunched in plastic waiting-room chairs or propped up in cots as they waited for a clinician to admit or discharge them, they were often grateful for a distraction.

Balancing the computer on their thighs, the patients held their pointer fingers over left and right keyboard keys. The heading “Life” appeared in the upper left corner of the screen, “Death” in the upper right. In the center, words associated with one of the headings popped up one at a time. Patients jabbed the left key to link “alive,” “survive,” “breathing,” “thrive” and “live” with “Life”; the right key matched “funeral,” “lifeless,” “die,” “deceased” and “suicide” with “Death.” The researchers asked the volunteers to do this as quickly as they could. Each word had a correct response. If patients put “thrive” with “Death,” for instance, a red X appeared, and the test paused until they hit the proper key. The sorting continued as the words reappeared randomly. After about a minute, the headers switched sides, and the process repeated. Then new rubrics popped up — “Me,” “Not Me” — along with new words to sort: “self,” “I,” “myself,” “my,” “mine,” “other,” “theirs,” “they,” “them,” “their.” Again the headers flipped places, and the sorting continued.

Once the patients had established a rhythm, the test began to measure bias. The headers doubled up: “Life” above “Me” and “Death” above “Not Me,” forcing test-takers to hit the same button to group “thrive” and “breathing” with “self,” “my” and “myself.” “Die” and “funeral” went with “theirs,” “they,” “them.” Theoretically, the faster the patients were and the fewer mistakes they made on this part of the test, the more they associated themselves with living.

Then “Life” and “Death” switched places, swapping the associations; the same key grouped “myself” and “my” with “funeral,” “suicide,” “die,” “deceased.” Agility on this part of the test would suggest an association with dying.

Doctors of all kinds, including psychologists, do no better than pure chance at predicting who will attempt suicide and who won’t. Their patients often lie about their feelings to avoid hospitalization. Many also appear to mislead by accident, not realizing they are a risk to themselves or realizing but not knowing how to say so. Some 90 percent of young people who kill themselves have visited their primary-care doctors within a year; nearly 40 percent of adults have within a month. The opportunity to help them seems enormous, if only there were a way to see past appearances and identify an inclination they might be hiding — perhaps even from themselves.

The Mass General patients and their clinicians rated on separate scales how likely they thought they were to try to kill themselves in the future. When researchers checked on each patient six months later, they discovered that, as expected, clinicians had fared no better than 50-50 in their predictions. Patients themselves, it turned out, were only slightly more accurate. The I.A.T., to everyone’s surprise, bested them both. People who sorted words more quickly when “Death” was paired with “Me” than with “Not Me” proved three times as likely to try to kill themselves as people who sorted words more quickly when “Life” was paired with “Me.” The I.A.T., it seemed, was picking up a heightened signal of suicidal tendencies that the most commonly used method for assessing risk — a clinical interview — had been powerless to detect.

On an unseasonably warm morning in January, a McLean Hospital van dropped Melissa off at Nock’s lab, where one of his postdoctoral researchers, Cassie Glenn, was running the I.A.T. and two other tests on volunteers from 12 to 19 years old. She had advertised for subjects on Craigslist and Twitter and through fliers in hospitals. About eight test-takers came in the past month, often on Sunday afternoons, in pink zip-up hoodies or jeans with holes in the knees, wearing Red Sox caps or glitter eye shadow. I met one girl who was giggly and two boys who were shy. Two volunteers were not yet 18 and brought their mothers. Glenn, a cheerful Roller Derby player with a colorful tattoo beneath each wrist, gave them a permission form they could sign to let me watch them take the tests or interview them. Protective of her subjects, she always asked that I wait out of sight so that they wouldn’t feel any pressure. Melissa was the fourth to sign on to meet me. When Glenn introduced us, Melissa held out her hand, listing slightly toward a purse with cartoon animals stitched on its side, slung over her opposite shoulder. “Would it be possible to take a break?” she asked Glenn. “Could I go downstairs and smoke a cigarette?” Glenn said yes, as long as she went with her. “You can come, too,” Melissa told me, “if you want to ask me questions.”

Outside, she perched on a bike rack, packing Marlboro Red 100s against her palm. I asked her why she volunteered for the tests, and she told me that in college, she took a psychology class in which she read about famous case studies. At McLean, curious about what it would be like to be a research subject, she asked her doctors how to become one. “I’ve always been interested, from an observer’s point of view, in what they would say about me,” she said. She paused, took a drag and gazed off down the street as she exhaled, playing the part of a tragic ingénue while making it clear that she knew she was onstage — that a real part of her was vulnerable to my opinion. Nock had told me that talking with people about their past suicide attempts does not increase the odds that they will try again. But I still worried about asking Melissa to revisit her experience. I wanted to know that she wouldn’t hurt herself again, but I couldn’t. I was afraid that if she did, I would feel responsible. It was, I realized, the same anxiety I heard from clinicians and researchers and family and friends who are involved with people thought to be at heightened risk for suicide. There was nothing I, or anyone else, could do to be absolutely certain she stayed safe.

We took the elevator back upstairs. In a tiny yellow room, Glenn settled Melissa in a wooden chair facing an ancient-looking P.C. Glenn and I watched through a tinted square window behind her. The first test was the Stroop, which psychologists use to identify words that are especially meaningful to the test taker. In Nock’s version, words appear on-screen in blue or red type, and as fast as possible the test-taker pushes one key if the word is red and another key if it’s blue. People who are contemplating suicide, knowingly or not, appear to take a fraction of a second longer to push the button when the word on the screen is related to suicide than when it is a neutral word like “engine” or “museum.” As Melissa hit the keys, the words barely registered as more than bursts of color: “happy,” “funeral,” “suicide,” “alone,” “museum,” “dead,” “pleasure,” “paper,” “pleasure,” “paper,” “rejected.”

Nock and his team are currently running the I.A.T. and Stroop at local and military hospitals as well as in the lab. They are also experimenting with other measures. Glenn later gave Melissa headphones and attached electrodes underneath her eye to measure how much a muscle there contracted when she heard a burst of noise meant to startle her. The noise was coupled with a series of pictures, some of which were related to suicide without being too graphic, like a man standing in front of a train. Glenn’s hypothesis is that teenagers have to overcome a fear of death to attempt suicide and that the less startled they are when looking at suicide-related imagery, the more likely they may be to try to kill themselves in the future. Nock’s plan is ultimately to combine four or five tests that measure slightly different cognitive processes into a single diagnostic tool that could deliver a risk score. But the scores Melissa and others get now will take on fuller meaning only over months and years of work — as researchers analyze them together in light of what the test-takers go on to do: become more or less depressed, start or stop having suicidal thoughts, hurt themselves in other ways or attempt suicide. Glenn would call Melissa in six months and again in a year to ask how she was doing and add those responses to her file.

If these data lead to reliable diagnostic tests, researchers could use them as a measuring tool to design studies of suicide that mirror the Framingham Heart Study, which has guided how we treat and prevent cardiovascular disease: 65 years ago, researchers began tracking the habits of and compiling regular medical workups on 5,209 residents of Framingham, Mass. It wasn’t initially clear what the data they were collecting meant. But over decades, as some people developed heart disease and others didn’t, their earlier test results and behavior began to reveal how high blood pressure and cholesterol, smoking, obesity and lack of exercise had helped cause it, how those factors could be entered into a calculator to determine risk and what would drive that risk down; once these insights led to treatments, the rate of deaths from heart disease nationwide, which had been steadily increasing since the turn of the century, began a steep decline.

Cognitive tests, of course, are not as fail-safe as a blood test. Nock says it is possible for patients taking the I.A.T. or the Stroop to adjust the speed of their keystrokes if they wish to hide their thoughts. “But it’s much more difficult to change the way you report on the test than to change the way you report verbally to someone.” Nock said. “It’s really easy to say: ‘I don’t want to kill myself. I’m totally fine.’ ” Anyone can choose not to reveal what he’s really thinking about. It’s much harder, Nock said, to trick the tests.

But even if the tests could offer a suicide-risk score right now, clinicians and researchers still have questions about how they would use the number to treat patients. “One of the things I wonder is what do you do if somebody tests positive on one of these things and they deny that they’re suicidal,” says David A. Brent, who holds an endowed chair in suicide studies at the University of Pittsburgh School of Medicine. “Admittedly I’d rather have the information than not. But it’s an interesting thing, you know, to say, ‘Look, according to this you are thinking about suicide.’ And would you be able to keep somebody in the hospital because of that? Would you change your treatment? I’m just not really sure.”

Nock’s refusal to accept any wisdom that can’t be tested, including the seemingly logical notion that simply getting more suicidal people into treatment would solve the problem, has put him at odds with clinicians who believe their methods work and that questioning those could cost lives. In January, in partnership with Ronald Kessler, an epidemiologist at Harvard, he published a study showing that about one in eight American teenagers reported experiencing serious suicidal thoughts. Strikingly, more than half of them were getting therapy before or during the period when they became suicidal. Some clinicians e-mailed Nock to express anger that he would make such statistics public. Their position, he said, was that if you tell people treatment’s not effective, they’ll stop coming. “But I think there’s a balance here,” Nock said. “Yes, we want people to get treatment. But at the same time, we want to make sure the treatment they are getting is effective.” Marsha Linehan, a psychology professor at the University of Washington, has shown that intensive therapy designed to change patterns of thinking and behavior can reduce the risk of attempted suicide among highly impulsive patients with severe emotional problems. This was the treatment Melissa received at McLean. Preliminary evidence suggests that other existing interventions might work too, but — largely because of how difficult it is to tell who is suicidal and when — a majority of people at high risk aren’t getting them.

A major investment of money and manpower from the Army is set to revolutionize the scope of collecting data on suicidal behavior. Nock and his team are participating in the Army Study to Assess Risk and Resilience in Servicemembers, which got under way in 2009 and is the most comprehensive investigation of suicide ever undertaken. The Army’s access to thousands of volunteers who lead comparable lifestyles and excel at following instructions offers a unique laboratory for Framingham-scale longitudinal studies. Nock envisions, for instance, one day beaming the I.A.T., Stroop and other tests to servicemembers’ phones daily — a technological feat unthinkable a decade ago. Those scores might reveal suicidal thoughts in real time. They might also offer a way to monitor patients known to be at high risk and call them if they seem to be entering a dangerous frame of mind.

“Right now, we ask people if they’re suicidal,” Nock said. “And if they say yes, we give them medication to try and make them less depressed or less anxious or less psychotic or to have a more stable mood. And then we talk to them. We do talk therapy. And essentially talk them into not being suicidal anymore. And this over all as a strategy for many people does not seem to be curative.” But if doctors could see which patients are suicidal at a given moment, they might be able to retrain their self-destructive thinking based on their test scores. If, as the I.A.T. seems to suggest, associating yourself more with dying than with living increases your risk for suicide, breaking that association might decrease it. To find out, Nock is developing computer tasks that he hopes could help get people, through rote practice, to identify more with being alive than dead. His researchers are also starting to test whether training people to think more positively about the past and the future makes them less likely to attempt suicide. Nock often talks about “turning levers,” as if he were a railroad-switch operator manning an existential junction. “Can we think of suicide as resulting from problems with memory or cognition or attention?” he said. “And if so, can we then turn levers on those things to make people less likely to think about suicide? So, it’s not giving a pill; it’s giving a training.”

Before I met Nock, I wondered what someone whose research requires constantly delving into the grief of others must be like. I imagined he would be solemn and weary. But he is a mechanic by background and temperament. His search for solutions is Socratic, not quixotic. He is an optimist. “It’s a complex problem,” he told me once, in his reasonable fashion, “but there are answers to it.” At this point in his career, he has asked hundreds of people why they tried to kill themselves. More often than not, their responses have fueled rather than dulled his curiosity.

One evening in his office in January, I asked him if he’d ever gotten an answer that did make sense to him. It was a school holiday, and most of the building was empty. Nock, working late, was wearing a tracksuit top and trying to kick a five-cups-a-day coffee habit by sipping a mug of apple cider. Outside, far below in the dark, snowflakes were slicking the roads.

Nock began to talk about pain. He imagined the building was on fire and that leaping from the window was the only way out. He evoked piercing ear infections that no drug could touch. He said he knows what it is like to be in intense pain and have an urgent need for it to stop, though he has never been suicidal. But he knows from his research that in most cases, feeling suicidal — for whatever reason — is a state that comes and goes. This is what drives him to turn levers, to keep asking people who attempt suicide, “Why?” As individual as their responses are, they tend to share at least one detail. “Virtually all of them,” he said, “say, ‘I’m glad I didn’t die.’ ”

Everyone wishes life could be different; no one’s first choice is to be dead. Melissa wants to be an actress or a writer. It upsets her, she told me, to think about the anguish her suicide attempt caused her family and friends, and she is working on building a life she can feel is worth living. But she has said there are also times when she faces an impulse to hurt herself again. She was always matter-of-fact when she talked about trying to kill herself — it felt, she said, like telling a story about somebody else. On the afternoon we met in the square, she seemed weary of rehashing the past and eager to get to class. She traced a wet mark along the table and spoke softly about what she euphemistically called her goodbye note. “The word ‘suicide’ kind of freaks me out,” she said, “so I try not to say it.”